The present invention relates to a sealing device and more particularly to a sealing device for sealing the cleaner and/or developer housing in electrostatographic reproducing apparatus.
In an electrostatographic reproducing apparatus commonly in use today, a photoconductive insulating member is typically charged to uniform potential and thereafter exposed to a light image of an original document to be reproduced. The exposure discharges the photoconductive insulating surface in exposed or background areas and creates an electrostatic latent image on the member which corresponds to the image areas contained within the usual document. Subsequently, the electrostatic latent image on the photoconductive insulating surface is made visible by developing the image with developing powder referred to in the art as toner. Most development systems employ a developer material which comprises both charged carrier particles and charged toner particles which triboelectrically adhere to the carrier particles. During development the toner particles are attracted from the carrier particles by the charge pattern of the image areas in the photoconductive insulating area to form a powder image on the photoconductive areas. Alternatively, single component development systems may be employed which utilize only charged toner particles. The thusly formed toner image may subsequently be transferred to a support surface such as copy paper to which it may be permanently affixed by heating or by the application of pressure.
In commercial applications of this process it is essential to contain the finely divided toner particles in their functional areas since if they are permitted to escape or circulate freely after a certain period of time, they will contaminate various functional surfaces rendering other functional elements of the process and the apparatus incapable of producing acceptable toner images. For example, they may be deposited on the imaging platen thereby creating background marks on any subsequent copy made from a document placed on the imaging platform. In addition, they may contaminate various electrical features such as the corona generating devices thereby rendering them ineffective in their charging or discharging functions. Finally, they can be a source of contamination to the prints produced therefrom and the operator of the machine. These difficulties are particularly encountered with the developer housing and the cleaner housing since these two housings contain substantial quantities of toner which if permitted to exit the respective housing will thoroughly contaminate the automatic printing machine rendering it incapable of performing its normal function. As a result, various types of sealing arrangements have been devised to contain developer and/or toner within the developer housing prior to its being consumed in the development process and also in the cleaner housing where residual spent toner is collected in a sump. These sealing devices takes various forms of implementation including the use of brushes, foams and combinations thereof. One of the most common types of sealing arrangements has been the use of a flat piece of a polyester film, Mylar, for example, in the form of a flap seal between the developer and/or cleaner housing and the imaging member. While satisfactory in many respects, difficulties are encountered with such a flap seal in that it is typically mounted as a flat strip by way of an adhesive or a clamp to the housing and any deviation or variation in the parallelism between the seal mount and the imaging member along its length will be observed between the deflected seal and the imaging member because the seal follows the mount and not the imaging member. In other words, small gaps may be formed in the interface between the deflected seal and the imaging member thereby permitting toner to escape. Furthermore, such use of adhesives or clamping devices in mounting the seal may introduce stresses into the flap seal with the formation of ripples at the seal edge, the edge becoming wavy providing small openings in the seal edge from which the toner may leak out. Accordingly, there is a desire provide a more effective seal in sealing the interface between the developer housing and/or a cleaner housing and the imaging member.